Background: The objective of this study was to evaluate the lips Morphology in Iranian adults with normal occlusion in Isfahan, Iran.
Materials and Methods: This cross-sectional study analysed the lateral cephalograms of 102 individuals aged 18 to 30 years with normal occlusion in Isfahan, Iran. Nine linear measurements (upper lip to S line (ULS), lower lip to S line (LLS), upper lip to B line (ULB), lower lip to B line (LLB), upper lip to E line (ULE), lower lip to E line (LLE), lower lip to H line (LLH), and upper and lower lip thickness), and 5 angular measurements (nasolabial, inferior labial, Z, upper lip prominence and lower lip prominence angles) were made on the lateral cephalograms. The study compared these measurements between males
and females using the Mann-Whitney and independent t tests (α=0.05).
Results: Assessment of lips morphology using 9 linear and 5 angular measurements showed variances in the mean values of several measurements compared to standard values reported by Ricketts, Steiner, Burstone, and Merrifield. Specifically, differences were observed in the ULE, LLE, ULS, LLS, ULB, and Z angle, while the LLB, LLH distances, and the nasolabial angle fell within the standard range. Additionally, males exhibited significantly greater upper and lower lip thickness compared to females (P<0.001). No other significant differences were found between males and females (P>0.05).
Conclusion: Most of the measured indices in the study population differed from the standard values reported in the literature, which highlights the need to take into account the Iranian norms in orthodontic treatment of Iranian patients.